This study is concerned with the development of children's imitative behavior in natural environment. Data were obtained on 30 children over a nine-month period during the second and third years of life. Sources of data consisted of descriptive accounts of imitation by mothers trained in observational recording. Mothers' records included children's immediate and delayed imitations. Frequently occurring categories included the imitation of positive and negative affective expression, mannerisms and idiosyncratic behaviors of others. A large number of incidents consisted in the imitative practice of instrumental skillls and interpersonal social competencies (e.g. household chores, self-care behaviors, affection and caretaking behaviors). Children also imitated aspects of parental disciplinary behaviors both in the context of controlling their own behavior and also when controlling the behavior of others. The implications of these findings for the environmental transmission of adaptive and disordered patterns of behavior are discussed.